HP Canvas Distortion / Shrinkage in Prints

HP Latex 330

Hi everyone. We are a boutique photographic lab based in Brisbane Australia. We recently took delivery of a 330 to replace our aging L25500. We've started using HP Premium Satin Canvas and are experiencing some worrying distortion (bowing) / shrinkage / contraction both horizontally and vertically across output. This fluctuates dependant on what point in the printing we are at and seems to lessen towards the end of longer jobs 5 metres or more. We are experiencing extremely high humidity here at the moment with 70-90% humidity so my thoughts are leaning towards that as the major contributor to this issue. As getting the productions area's humidity levels down is not a possibility are there any other options available to me? I assume increasing suction won't do a lot in this situation. We're in the middle of Christmas madness so any help would be greatly appreciated. Many thanks. Will

In your case I think we could have different effects acting at once. First of all I'll recommend you to eliminate the media bowing. This can be done with the Straightness Optimization Plot. See the forum topic below:

L360 - Straightness Optimization Plot

Once the bowing corrections are introduced, the length should be consistent, if not I'll recommend you to use the TUR with this jobs in order to reduce the tension applied in the front of the media.

To sum up, I'll recommend you to follow the steps below:

Set the straightness optimization parameter to compensate the bowing

Print without the take up reel to reduce the front tension

Reduce temperatures

If left, right and center lengths are even but then this length has an offset correct this offset via RIP